I cleaned the top surfaces pretty good with a microfiber and brake fluid, but now need to open the throttle and get inside a bit. I would think the edge of the butterfly valves need to be cleaned as most important, but in opening the throttle 1/2 of the valve will flip downward making it harder to clean. Anyone cleaned these before & share techniques? Even a small toothbrush would be hard to get the flipped down portion of the valve when I open the throttle .
I was able to open up the throttle to clean the walls under the valves, but in doing so I saw that while pushing the throttle all the throttle body valves on the right side of the engine were not opening as far as the left side of the engine. Makes me wonder if this may be the cause of the rough running issue or not. I'm no engine guy but I would think the right side should be opening pretty much the same as the left. In the photos below show two throttle bodies (#1 is the left rear side and #5 is the right rear).
Yeah, need to get them synchronized, assuming it is just across the two banks you can get pretty close with drill bit shanks as a 'feeler' gauge to adjust the right side to match the left.
Hey thanks for the drill bit gauge idea. The company said I need to get both sides set at .002 inch feeler gauge with the valves at rest. Says I need to disconnect the cross link (#3) in the photo then adjust the valves and reset the link to neutral. All left side is already perfect at .002, but of course all the right side is too tight at rest. Plan is to get this bitch adjusted today, getting tired of being in the engine bay with numb legs. Usually I'm just in there 8 hours polishing, but this is something else. I guess one benefit is I'm learning something as I go. Not sure if this is my problem issue, but at least the valves should be adjusted correctly if I don't screw something up worse. 
Be careful when adjusting that cross-link, Jan. One friend with an 8-stack EFI system would NOT hold a stable idle. It ran perfect when cold but different when hot. After much screwing around, it was discovered that aluminum heads and intakes expand when hot and his hot engine was pulling on the cross link enough to change the idle from 700 to 1400 rpms. I think the fix was simply to readjust when hot and accept however it was when cold.
The hexagonal cross link in your photo looks decidedly bent, it takes a lot of force to bend one, I wonder what happened and whether that isn't the change you see?
Hot damn you're pretty observant. I have had my head above that engine for a couple days looking at how all the parts work and trying different adjustments. But definitely something is off with the mechanisms that are operated by the throttle. I also pondered weather that cross link got bent or was purposely bent initially so that it enables it to pass under the fuel rails without hitting them because it is pretty tight. So I tried turning it sideways and the left side still opens fully and hits the stop long before the right side opens fully. I'm no mechanical engineer so I'm not sure if turning it sideways would make any difference in the "rate" that it opens the left side, but I tried it anyway and no difference. The right side does work and open fully as shown in the second photo but you have to disconnect the cross link. I asked the manufacturer maybe there are different sizes of levers as shown in the third photo, maybe the black lever should be shorter or longer to slow the rate of the left engine side opening so fast.
Manufacturer says the linkage is not correct for the left side valves to open quicker and fuller than the right side, but I'm not sure if it came that way years ago from the manufacturer or if someone modified the linkage arm when building the engine. He did say the cross linkage is correct to be slightly bent so it travels under the rails when pressing the throttle. But anyway I have to take things apart and send him the valves & linkage so he can update everything so I need to stick my head in there and see how to disconnect things. But the funny thing is that I adjusted all the valves to his specs at rest (.002 inch) and figured to start the car and see how things run on idle with valves still resting and the engine raced to about 2,500 RPM and backfired, wife crapping the pants in the livingroom. I assume maybe that was due to the Speed-Pro ECU still programed back in the day with dirty valves and now with clean valves and the .002 correct adjustment now things don't match up with the ECU. That is unless something else is still wrong. Finally found my compression gauge in the attic, so I'm going to get to that first. So glad I'm retired to mess with it on and off, but I really would like to drive!
If it were me I'd send the entire manifold fully assembled. There has to be a root cause.
Thanks, I offered that up to send the whole unit back but he just wants the valves and linkages. If I'm thinking correctly, if the throttle arm on the right that pushes the cross link to the valves on the left side of the engine was shorter, that should allow the left side valves to open slower (and hopefully match the right side). As far as the engine revving too high on start up & idle after I adjusted to .002 inch, I may close the gap on the valves a little more and see what happens. I am assuming high rev idle could be from the valves still too open, because that wasn't my problem before cleaning & adjusting things (In fact the idle was like 100 RPM). Im just kind of surprised the engine ran so well all these years with the right side valves not opening as much as the left side.
Ugh, went to check compression by hooking up a remote starter to the starter so that I could turn the car over without the fuel pump going (such as would be the case turning the key on). However that did not work I am thinking because the car has an alarm and maybe that would prevent the car from starting that way unless the key was in the on position. So I am wondering how to disable the fuel pump. Shouldn't there be a fuel pump fuse? I looked in the Pantera manual fuse panel but don't see any fuel pump fuse. I am learning the more these cars are modified, the more difficult they become to work on.
Hi Jan.
The original Pantera’s had a mechanical fuel pump, therefore no fuel pump fuse in the fuse box.
Yours may have a in-line fuse, but you’d have to trace the wires from the fuel pump to wherever it’s powered from.
There may also be Bullet or spade connectors close to the fuel pump. Fuel pumps typically only come with very short leads.
Good luck
Rocky
You can also simply disconnect the electrical connectors of the 8 injectors
Many of the aftermarket EFI systems use a fuel pump relay. You should trace the wires back from the fuel pump to its source. When you find the relay, you can just disconnect it.
Thanks guys, I believe this is the fuel pump. I put my jack away already, so the red wire is easier to get at than the black. Maybe I could just disconnect the red wire & put some electrical tape on the connection or do both wires need to be disconnected to disable the pump? I couldn't find any fuse or other disconnect near by.
Disconnecting the red lead will be fine, just be sure to unhook the battery while you are doing it as it's tight and easy to short the wrench to the body of the pump.
Encountered another thing, looks like there are two solenoids on this car, one on the starter and one shown here. Not sure which two leads to connect with my remote starter so I can crank the engine to do compression check. I was connected to the solenoid on the starter itself so maybe that's why it would not start. Look forward to sometime in 2021 to get this back on the road.
Connected my remote starter to post 1 and 4 shown in the diagram above and pushed the remote starter button to do compression test but the car still would not turn over. Not sure how else to connect it so I can use my remote starter. I kind of wanted to watch the compression gauge as I turned it over 5 revs, but no luck. So I thought well I will just use the key and turn it over 5 revs then go look at the compression gauge since I already disconnected the fuel pump. But then when I turned the key to the on position I still heard this loud rumble as noted in the video below. I always thought that noise was the fuel pump noise so I was surprised to hear it when I turned the key on. Now I wonder if the fuel pump is really disengaged or if that noise is something else. I would hate to turn the car over with fuel present in doing the compression test.
Sure sounds like a fuel pump to me. Do you have a vacuum pump for your brake booster? If so, that's probably what you're hearing.
Yeah maybe the booster, wife said the noise was coming from the front. So I turned it over with the key for 5 or so strokes and the best I got was 90 on the gauge (not good, I understand 120 & above is about norm). Retested a couple times and still 90. That was on the questionable cylinder that had the low header temp reading. So I'm going to put new plugs in anyway all around and check each cylinder while I'm at it.
